Deswelling Mechanisms of PNIPAM Grafted in Nanochannels: A Molecular Dynamics Simulation Study.

Porous thermosensitive hydrogels exhibit a more flexible strategy for freshwater capture compared to conventional hydrogels. This study employs molecular dynamics (MD) simulation to investigate the deswelling behavior of poly(N-isopropylacrylamide) (PNIPAM) grafted within the nanochannel, aiming to elucidate the deswelling elimination process at various temperatures. Notably, a distinct phase separation is observed at specific temperatures above the lower solution temperature (LCST). Furthermore, this study takes the effect of heat flux into account, wherein distinct heat fluxes lead to varying levels of phase separation between water and the polymer. Specifically, the number of hydrogen bonds, volume of polymer chains, and density distribution of water molecules are statistically analyzed to reveal the mechanism of phase separation in a thermosensitive hydrogel. These findings provide insight into the accelerated deswelling kinetics of the PNIPAM polymer chain, which has guiding significance for the field of water harvesting by the enhancement of the water release capacity in thermosensitive hydrogels.

Typical Application of Sound Field in Wastewater Treatment with Fluidized Bed Photocatalytic Reactor.

The effect of a sound field on wastewater treatment with a fluidized bed photocatalytic reactor (FBPR) was investigated. With Alizarin Green (AG) being the sole infectant, the Fe-doped TiO2 catalyst prepared was used as the fluidized media. According to the Langmuir-Hinshelwood model, the photocatalytic degradation follows the pseudo-first-order reaction kinetics with respect to the concentration of AG. Sound field application allowed the fluidization of the fine powder at high liquid flow rates; thus, the mass transfer rate between organic pollutant and particle photocatalyst was enhanced and the efficiency of degradation was increased. As expected, the degradation rate constant increased with increasing sound pressure level, as well as increased with increasing sound frequency ranging from 50 to 100 Hz, then further decreased with increasing sound frequency from 100 to 200 Hz. In addition, Fe doping is also responsible for the enhanced photocurrent response of the Fe-doped TiO2 nanoparticle in FBPR relative to pure TiO2.

3-(4-Carb-oxy-5-carboxyl-ato-1H-imidazol-2-yl)pyridin-1-ium monohydrate.

In the zwitterionic mol-ecule of the title compound, C(10)H(7)N(3)O(4)·H(2)O, one carboxyl group is deprotonated and the pyridine N atom is protonated. The pyridinium and imidazole rings form a dihedral angle of 5.23 (1)°. An intramolecular O-H⋯O hydrogen bond occurs. In the crystal, inter-molecular N-H⋯O, O-H⋯N and O-H⋯O hydrogen bonds link the zwitterions and water mol-ecules into sheets parallel to (102).

Immunostimulatory activities of Bacillus simplex DR-834 to carp (Cyprinus carpio).

A bacterial strain, designated DR-834 and producing immunostimulatory activities to carp (Cyprinus carpio), was isolated from Qinghai-Tibetan Plateau permafrost soil. Cultural characteristic studies suggested that this strain belongs to the genus Bacillus. The nucleotide sequence of the 16S rRNA gene of strain DR-834 exhibited close similarity (99%) with the 16S rRNA gene of Bacillus simplex. Two compounds showing potent activity were isolated from secondary metabolites of the strain through bioassay-guided isolation techniques and identified by spectral data (infrared, nuclear magnetic resonance and mass spectrometry) as: (1) 4-trans-hydroxy-l-proline and (2) cyclo-(l-Pro-Gly)(2). They were found to be significantly increased the selected innate immune function parameters, serum SOD activity, serum lysozyme activity, serum bactericidal activity, superoxide anion production and phagocytic activity by isolated blood leucocytes. The effects of two compounds on immune-related genes expression were further investigated. The outcomes of real-time quantitative polymerase chain reaction (RQ-PCR) proved that the transcribing level of interleukin 1beta (IL-1beta) and inducible nitric oxide synthase (iNOS) mRNA in the blood have been augmented by 4-trans-hydroxy-l-proline and cyclo-(l-Pro-Gly)(2). Compounds 1 and 2 administration the challenge with live Aeromonas hydrophila decreased the percentage mortality in the experimental groups with the consequence increase in relative percent survival (RPS) values. Compound 2 produced the highest protection with the RPS values of 87.50, 77.78, 55.56 and 55.56 after 1, 2, 3 and 4 weeks, respectively. The study indicates that the isolated compounds could be positively influence the immune response and protect the heath status of carp against A. hydrophila infection.

Overlapping spectra resolution using non-negative matrix factorization.

Non-negative matrix factorization (NMF), with the constraints of non-negativity, has been recently proposed for multi-variate data analysis. Because it allows only additive, not subtractive, combinations of the original data, NMF is capable of producing region or parts-based representation of objects. It has been used for image analysis and text processing. Unlike PCA, the resolutions of NMF are non-negative and can be easily interpreted and understood directly. Due to multiple solutions, the original algorithm of NMF [D.D. Lee, H.S. Seung, Nature 401 (1999) 788] is not suitable for resolving chemical mixed signals. In reality, NMF has never been applied to resolving chemical mixed signals. It must be modified according to the characteristics of the chemical signals, such as smoothness of spectra, unimodality of chromatograms, sparseness of mass spectra, etc. We have used the modified NMF algorithm to narrow the feasible solution region for resolving chemical signals, and found that it could produce reasonable and acceptable results for certain experimental errors, especially for overlapping chromatograms and sparse mass spectra. Simulated two-dimensional (2-D) data and real GUJINGGONG alcohol liquor GC-MS data have been resolved soundly by NMF technique. Butyl caproate and its isomeric compound (butyric acid, hexyl ester) have been identified from the overlapping spectra. The result of NMF is preferable to that of Heuristic evolving latent projections (HELP). It shows that NMF is a promising chemometric resolution method for complex samples.